# Existing Facilities Energy Conservation Assessment

Most of the energy efficiency optimization activities at the present time and worldwide are in the retrofit category. Many industrial facilities are ravenous to save energy and to make more with less, due to economic reasons and in many applications for moral social responsibility, too. Energy efficiency assessment team normally consists of energy efficiency consultants, energy engineers, process engineers, simulation and modeling engineers and plant’s senior process and utilities engineers as well as plant’s senior operators.

## Existing Facilities Energy Conservation Assessment

In the upcoming part till the end of this chapter we are addressing such important engineering work.

### Problem Statement

“Given an industrial facility that consists of several processes and utility plants, define; targets for energy utility systems supply to the process and targets for energy consumption minimization. Find a list of possible operational and design modifications to achieve desired target(s). Conduct the related engineering activities in minimum possible time using available plant data and without interruption to the business as usual of the production facility”

### Problem Formulation

Conceptually this problem can be formulated as a bi-level programming problem where we have two objectives, the minimum disruption in the energy utility supply (zero deficiency) and minimum consumption of energy utility.
In such cases, the energy utility is minimized subject to minimum energy deficiency supply.

The outer problem of optimization of minimum energy consumption should be solved at the best case scenario of the inner problem which is the least possible deficiency in energy utility supply to the process.

### Solution Approach

Since mathematical programming/optimization techniques are time consuming; difficult to solve globally and in many applications demand a high level of human expertise; we are proposing a solution of the problem through decomposition techniques.

Simply the plant’s energy utility needs will be defined with reasonable levels of flexibility and the energy utility system; electricity, fuel, steam and other energy-related utilities will be scrutinized one by one to find the near-optimal consumption of such utilities that guarantees minimum deficiency in the utility supply to plant processes.

On the macro level, the energy system components are generation, distribution and utilization.

Our objective will be to minimize: waste in energy, fresh resources and capital (de-bottlenecking) in these three components. This can be done via the continuous upgrade of the efficiency of energy system components in generation, distribution and utilization. However, as mentioned before in the introduction of this book, the utilization component has a unique feature, where its boundaries are not completely dictated by the process. Therefore, the room of improvement in this component is much wider than others.

### Other Info

Document Category Engineering